Sprocket-pin driver for motion-picture machines



C. W RYDER.

SPROCKET PIN DRIVER FOR MOTSON PICTURE MACHINES.

- APPLICATIQH FILED ocnz. 1919.

1,381,667, Patented June 14, 1921- Inc/9% UNITED STATES PATENT OFFICE.

CHARLES W. RYDER, OF CHICAGO, ILLINOIS, ASSIGNOB OF ONE-HALF TO WILLIAM DIEIZ, OF CHICAGO, ILLINOIS.

Specification of Letters Patent.

Patented June 14, 1921.

Application filed October 2,1919. Serial No. 327,988.

T 0 all whom it may concern:

Be it known that I, CHARLES WV. RYDER, a citizen of the United States of America, and a resident of Chicago, county of Cook, and State of Illinois, have invented certain new and. useful Improvements in Sprocket-Pin Drivers for Motion-Picture Machines, of which the following is a specification.

The main objects of this invention are to provide an improved form of tool for inserting and removing tapered pins into and from the film sprockets of motion picture machines; and to provide an improved form and arrangement of the parts of such a tool whereby it may be readily brought into accurate alinement with the pin, avoiding any possibility of bending either the pin or the sprocket arbor.

An illustrative embodiment of this invention is shown in the accompanying drawings, in which Figure 1 is a side view partly in section showing the improved tool in position for removing one of the tapered pins of a film sprocket.

Fig. 2 is a side elevation taken from the right of Fig. 1, the parts in section being in the plane of the line 22 of Fig. 1.

Fig. 3 is a fragmentary sectional view of the screw-threaded punch showing the concave seat for engaging the pins.

The improved tool is particularly designed for use with the common form of motion picture film sprocket which comprises a hollow shaft or quill 1 having a peripherally toothed drum 2 rigidly mounted at each end thereof, said quill having a pair of apertures 3 extending therethrough and spaced inwardly at equal distances from the sprocket drums. The sprocket is supported on the driven shaft 4 of the motion picture machine and is secured against relative rotation by a pair of tapered pins 6 which extend through the apertures 3 of the quill and engage corresponding apertures in the arbor.

I-leretofore the insertion and extraction of the pins 6 has been effected by the blows of a hammer or similar tool. This has frequently resulted in bending the driven shaft 4, as a result of which a swaying motion has been imparted to the revolving film, causing serious vibration of the pictures flashed on the screen.

The frame of the improved tool coma yoke .7 having pa r of sidewi e extending parts 8 and 9. The part 8 is formed to provide a V-shaped seat 10 and the part 9 is provided with a threaded aperture 11 for supporting the screw 12 which is longitudinally adjustable toward and away from the seat 10 by means of a crossbar or handle 13 at the outer end thereof. The inner end of the screw12 is reduced in diameter to form slender stem or punch 14L, the end of which is concaved to provide a seat 15 which fits the end of the pin acted upon. An aperture 16 extends through the part 8 of the yoke and is arranged in alinement with the longitudinal axis of the screw 12, said axis being equally distant from the side faces of the yoke 7. The yoke is constructed of sufficient thickness so that the distance between the stem let and each side face of the tool is equal to the distance between the apertures 3 of the quill and the inner faces of the respective drums 2.

In the operation of extracting a pin, the tool is applied to the sprocket with the seat 10 engaging the quill l, and. is shifted along the quill until the yoke abuts against the sprocket drum adjacent the pin which is to be removed. By rotating the sprocket or the tool. the pin 6 may be brought into alinement with the stem 14., due to the fact that the stem 14 and pin are equally spaced from the sprocket drum when said drum and yoke are in abutting relation. By adjusting the screw '12 the tapered pin is forced from the quill through the apertures 16 of the tool.

Although but one specific embodiment of this invention has been herein shown and described, it will be understood that some of the details of the construction shown may be altered or omitted without departing from the spirit of this invention as defined by the following claims.

I claim:

1. A tool of the class described, comprising a yoke having an extended part having on its upper face a transverse V-shaped seat, and a screw-threaded member supported on said yoke and axially adjustable toward and away from said seat, said extended part having an aperture therethrough in alinement with the longitudinal axis of said screwthreaded member, said member being adapted to effect the insertion or extraction of a pin into and from a shaft supported in said V-shaped seat.

2 A. tool of the clas described for u e With a motion picture machine film sprocket wherein a hollow quill having a pair of spaced sprocket drums is provided with a pair of apertures for tapered pin connection to an arbor said tool comprising a yoke having opposed parts one having a seat for said quill, and the other supporting a screwthreaded member so as to be longitudinally adjustable toward and away from said seat,

said seat having an aperture extending therethrough in alinement with said a screwthreaded member, the Width of said yoke being proportioned to bring said screwthreaded member into the plane of the adjacent said tapered pin when said yoke is in abutting relation with'the inner face of either said drum.

Signed at Chicago this 27 day 01" Sept,

CHARLES W. RYDER. 

